Zero adjusting device for scales



Y @TRAQHAN ZERO ADJUSTING DEVICE FQR SCALES Filed Aug. 1Q 1925 l THOMAS H. S-TRACHAN, F DAYTON, OHIO, ASSGNOR TO DAYTON SCALE COMPANY, OF

i DAYTON, OHIO, A CORPORATION 0F NEW JERSEY.

zniao museums DEVICE non scams.

Application filed.- August 1, 1925.' Serial No. 47,1173.

in range of the'indicator travel may be secured by varying the leverage which .acts

upon the load counterbalancing spring.

Referring to the drawings, Fig. 1 shows a front elevation view of a scale embodying. my improvements. The' above casing is broken away to show interior construction.'

Fig. 2 shows a. bottom view of certain of the parts in the base of the scale, the view being taken as indicated by arrows 2-2 o n Fig. 1.

Fig. 3 1s a detail sectional view, the sec' tion being taken online 3 3 of Fig. 2.

rlhe scale comprises the usual pan 10, pivotally supported upon lever 11 carrying a sector rack 12 meshing with an indicator gear segment 13 arranged to move the indicator 14 in the usual manner over chart 15. As in the previous Hopkinson patent, a bimetallic thermostatic element is provided in the base ofthe scale, this element being designated 16.' The element is preferably sup# parted at one end by boss 17. A spring Aclip member 18 isl adjustably supported upon the end of the thermostatic element 16 by screws 19 which are threaded into the thermostaticv element and -which extend through slots 20 in clip member 18. The load counterbalancing spring 21 is attached to the clip member 18 and also to the lever 11.

Adjustment of the scale zero position is preferably 'effected by means of a stud 22, which stud is threaded to cooperate with threads in the base housing at its upper end and is also slotted as indicated at 23 to receive a screw-driver'or like implement. The lower end of the stud 22 bears upon a' crosspiece 24, which cross-piece or bridge member vis loosely guided at its'ends by studs 25 and 26 which are threaded into the base casing. llt will he understood that by screwing down on stud 22, member 24: will be pressed down ing a block 30 relative to the lever. block 30 is slotted as shownat 31 to receiverocking about 25 and thereby pressing downwardly upon the bi-metallic thermostatic member 16 which directly underlies the member 24. By properly adjusting the stud 22, greater or less tension may be applied to the spring whereby an adjustment of the scale zero may be obtained.

The range of travel of the scale indicator 15 may be also varied by adjusting spring clipl member 18 in or out relative to part 16 which supports it.

The point of connection of the spring 2l to the lever 11 may also be varied by adjust- This clamping bolt 32.

'llhe use of the loose cross piece bar or member'24 provides for imparting adjusting movement to the thermostatic bar without marring the bar during the adjusting operation, thus preventingthe effecting of irregular adjustments.

l claim- L A'scale having a base housing, a thermostat bar carried thereby, and having a load counterbalancing spring connected therewith, means for adjusting the zero of' thescale comprising a stud threaded in the housing for adjustment relatively thereto and a loosely supported cross piece overlying the thcrmostatic bar and underlying the end of the stud tol position the thermostatic bar. 2. A sc'ale having a base housing, a spring supporting bar carried by said base, a bridge member overlying said bar and loosely supported at its ends by said base housing, and a Zero adjustment screw bearing at its end upon said bridge member for the purpose vdescribed.

3. A weighing scale having a lever, a thermostatio bar, a spring connected to said bar and said lever, and a clip support for said spring adjustably secured upon said bar so as to be4 capable oflongitudinal adjustment thereon for the purpose described.

4. A weighing scale having a scale lever, a thermostatic bar and a load counterhalancing spring connecting said bar and lever, means-connecting said lever and spring adjustable to shift the spring longitudinally of the lever for the purpose described.

5. A weighing scale having a scale lever, a thermostatic bar and a load counterbalancing spring connecting said bar and lever,

means connecting said bar and spring acijustable to shift the spring longitudinally of the bar oif the purpose' described.

6. A Weighing scale having e, Scale lever, a tbermostete bai', a load counerbalanoing spring connecting' said bar and iever, means connecting said bei* and said Spring and adb justabe iongi'udinaly of che bei Wheeb] lthe spring may be moved along the bur, and

2L Connection between said lever and said i0 spring adjustable longitudinally of the lever whereby the Spling may be moved along seid lever.

n testimony whereof hereto affix my Signature.

THMAS H. STRACHN. 

